Patho Chapter 8
For which acid-base imbalance will the nurse monitor for a client taking large doses of loop diuretics? Metabolic acidosis Respiratory acidosis Metabolic alkalosis Respiratory alkalosis
Metabolic alkalosis Explanation: Loop and thiazide diuretics commonly cause metabolic alkalosis as a result of hydrogen and potassium ion excretion in the urine. This leads to increased reabsorption of bicarbonate leading to metabolic alkalosis.
Hypothalamic sensory neurons that promote thirst when stimulated are called: Baroreceptors Chemoreceptors Thermoreceptors Osmoreceptors
Osmoreceptors Explanation: Sensory neurons, called osmoreceptors, which are located in or near the thirst center in the hypothalamus, respond to changes in the osmolality of extracellular fluid by swelling or shrinking.
A nurse caring for a client with a diagnosis of diabetes insipidus (DI) should prioritize the close monitoring of which electrolyte level? Potassium Sodium Magnesium Calcium
Sodium Explanation: The high water intake and high urine output that characterize diabetes insipidus create a risk of sodium imbalance. DI may present with hypernatremia and dehydration, especially in persons without free access to water, or with damage to the hypothalamic thirst center and altered thirst sensation.
Which unit of measure best describes the concentration of solute in a particular volume of fluid based on electrolyte equivalency? mg/dL dL mEq/L mEq
mEq/L Explanation: The amount of electrolytes and solutes in body fluids is expressed as a concentration or amount of solute in a given volume of fluid, such as milligrams per deciliter (mg/dL). The millequivalent is used to express the charge equivalency for a given weight of an electrolyte and is expressed as milliequivalents per liter (mEq/L).
The nurse has just received the lab results of a client's calcium level. The nurse identifies a normal calcium level as: 9.0 to 10.5 mg/dL (2.25 mmol/L to 2.63 mmol/L)) 12.0 to 15.0 mg/dL (3.0 to 3.75 mmol/L) 13.5 to 14.5 mg/dL (3.38 to 3.63 mmol/L) 3.5 to 5.3 mg/dL (0.88 to 1.32 mmol/L)
9.0 to 10.5 mg/dL (2.25 mmol/L to 2.63 mmol/L)) Explanation: The normal range for calcium is 9.0 to 10.5 mg/dL. A decreased level of calcium is 3.5 to 5.3 mg/dL. Elevated levels of calcium include 12.0 to 15.0 mg/dL and 13.5 to 14.5 mg/dL.
In which client would the nurse be most likely to assess the signs and symptoms of an acid-base imbalance? A client with chronic obstructive pulmonary disease (COPD) whose most recent arterial blood gases reveal a PCO2 of 51 mm Hg A client who has been admitted with a traumatic head injury and whose intracranial pressure is 18 mm Hg A laboring client who is receiving an oxytocin infusion and who has been in the second stage of labor for 7 hours A client with a fluid volume deficit who has been receiving intravenous 0.45% NaCl for over 48 hours
A client with chronic obstructive pulmonary disease (COPD) whose most recent arterial blood gases reveal a PCO2 of 51 mm Hg Explanation: An elevated PCO2 is commonly associated with respiratory acidosis because excess CO2 ultimately increases the concentration of H+ ions. Increased intracranial pressure, oxytocin infusion, and the administration of hypotonic fluids are not directly linked to common alterations in acid-base balance.
Body weight consists of which percentage of body water?
Body water equals 60% of body weight.
The nurse recognizes the role of the lungs in acid-base balance is regulation of which of the following? CO2 H2O HCO3 Hydrogen
CO2 Explanation: Carbon dioxide (CO2) is regulated by the lungs. HCO3 and H+ are regulated by kidneys.
The nurse caring for a client with respiratory acidosis examines arterial blood gas (ABG) results. Which change from the initial value indicates the client's respiratory acidosis is improving? pH has decreased CO2 has decreased HCO3- has decreased O2 has decreased
CO2 has decreased Explanation: In respiratory acidosis, the client has a net gain of carbon dioxide (CO2), which creates a drop in pH. The pH needs to move away from acidosis, which is the low end of the pH scale, for the client's condition to demonstrate improvement. To raise the pH, either the carbon dioxide (CO2) level needs to decrease or the bicarbonate level needs to increase. Oxygen (O2) concentration is reported on ABG results, but does not indicate acid-base balance.
The nurse is caring for a client with isotonic fluid volume deficit. The nurse should anticipate which clinical manifestations? Select all that apply. Decreased urine output Hypotension Tachycardia and weak pulse Increased hematocrit and BUN Weight gain Decreased body temperature
Decreased urine output Hypotension Tachycardia and weak pulse Increased hematocrit and BUN Explanation: Isotonic fluid volume deficit results when water and electrolytes are lost in isotonic proportions. It is almost always caused by a loss of body fluids and is often accompanied by a decrease in fluid intake. The manifestations reflect a decrease in extracellular fluid and include thirst, loss of body weight, decreased output, impaired temperature regulation, concentration of blood cells and BUN, and a decrease in arterial and venous volumes. Increased body temperature reflects fluid volume deficit.
The nurse is caring for a client who receives hemodialysis. The nurse knows that hemodialysis involves movement of charged or uncharged particles along a concentration gradient. Which function best describes this process? Diffusion Osmosis Evaporation Osmotic pressure
Diffusion Explanation: Diffusion is movement of charged or uncharged particles along a concentration gradient. Osmosis is the movement of water across a semipermeable membrane.
A nurse observes peaked, narrow T waves on the electrocardiogram of a client suffering from renal failure. The nurse suspects that the client is experiencing which condition? Hypokalemia Hyperkalemia Hyponatremia Hypernatremia
Hyperkalemia Explanation: As potassium levels increase, disturbances in cardiac conduction occur. The earliest changes are peaked, narrow T waves and widening of the QRS complex.
A nurse is caring for a client with hypoparathyroidism. Which imbalance is a major concern for the client? Hypocalcemia Hypokalemia Hyponatremia Hypernatremia
Hypocalcemia Explanation: Hypoparathyroidism reflects deficient parathyroid hormone (PTH) secretion, resulting in hypocalcemia. The main function of PTH is to maintain the calcium concentration of the extracellular fluid.
A nurse is caring for a client admitted with diabetic ketoacidosis who is being treated with intravenous (IV) insulin administration. The client develops symptoms of anorexia, nausea, vomiting, constipation, and abdominal distention. Bowel sounds are hypoactive. Based on these symptoms, which electrolyte alteration should the nurse monitor for? Hypokalemia Hypernatremia Hypophosphatemia Hypocalcemia
Hypokalemia Explanation: Insulin increases the movement of glucose and potassium into cells; therefore, potassium deficit often develops during treatment of diabetic ketoacidosis.
Lymph fluid arises directly from which space? Intercellular Plasma Interstitial Intravascular
Interstitial Explanation: The lymphatic system represents an accessory route whereby fluid from the interstitial spaces can return to circulation. More important, the lymphatic system provides a means for removing plasma proteins and osmotically active particulate matter from the tissue spaces, neither of which can be reabsorbed into the capillaries.
A client has these arterial blood gas values: anion gap 20 mEq/L (20 mmol/L), pH 7.29, PCO2 37 mm Hg (4.92 mmol/L), HCO3- 11 mEq/L (11 mmol/L), base excess -6 mEq/L (-6 mmol/L). With what condition do these values correspond? Lactic acidosis Hyperkalemia Multiple myeloma lithium toxicity
Lactic acidosis Explanation: Anion gap (AG) is the difference between the plasma concentration of sodium ions and the sum of the measured anions (chloride and bicarbonate). Normally, the AG value should be between 8 and 16 mEq/L. AG will rise above normal for conditions that commonly cause acidosis such as lactic acidosis and ketoacidosis. Hyperkalemia, lithium toxicity, hypercalcemia, hypermagnesemia, and multiple myeloma will cause a drop in the AG by raising the level of unmeasured cations. ABGs measure pH, carbon dioxide (PCO2), bicarbonate ion (HCO3-), oxygen (PO2), base excess, and the anion gap. A pH that is below 7.35 is considered acidic. The PCO2 is the primary indicator of respiratory function and falls between 35 and 45mm Hg. Bicarbonate (HCO3-) is the primary indicator of metabolic function and is acidic if below 22 mEq/L. Base excess measures the level of all the buffer systems in the blood. If the level is more than 0.2 mEq/L below the normal pH of 7.4 it is considered deficit and indicates metabolic acidosis.
Pressure generated as water moves across a membrane is also known as which of the following? Osmotic pressure Hydrostatic pressure Filtration pressure Lymphatic pressure
Osmotic pressure Explanation: Osmosis is the movement of water across a semipermeable membrane. As with particles, water diffuses down its concentration gradient, moving from the side of the membrane with the lesser number of particles and greater concentration of water to the side with the greater number of particles and lesser concentration of water. As water moves across the semipermeable membrane, it generates a pressure called osmotic pressure.
Vitamin D, officially classified as a vitamin, functions as a hormone in the body. What other hormone is necessary in the body for vitamin D to work? Thyroid hormone Parathyroid hormone Antidiuretic hormone Angiotensin II
Parathyroid hormone Explanation: The small, but vital, amount of ECF calcium, phosphate, and magnesium is directly or indirectly regulated by vitamin D and parathyroid hormone.
Which conditions place clients at risk for developing respiratory acidosis? Select all that apply. Diabetes mellitus Pneumonia Kyphoscoliosis Morbid obesity Drug overdose
Pneumonia Kyphoscoliosis Morbid obesity Drug overdose Explanation: Respiratory acidosis is caused by conditions that suppress respirations or impair alveolar ventilation. These include drug overdose, head injury, lung diseases such as asthma, emphysema, chronic bronchitis, pneumonia, pulmonary edema and respiratory distress syndrome. Airway obstruction also causes respiratory acidosis. This could be caused by chest injury, kyphoscoliosis (spinal curvature), extreme obesity, or treatment with paralytic medications.
A nurse is caring for a client with a low sodium level and increased water retention. Hematocrit and blood urea nitrogen levels are decreased, urine osmolality is high, and serum osmolality is low. A chest x-ray shows a possible lung mass. Based on these findings, which problem could the client be diagnosed with? Syndrome of inappropriate antidiuretic hormone (SIADH) Diabetes insipidus Liver disease with ascites Hyperglycemia
Syndrome of inappropriate antidiuretic hormone (SIADH) Explanation: The syndrome of inappropriate ADH (SIADH) results from a failure of the negative feedback system that regulates the release and inhibition of ADH. In people with this syndrome, ADH secretion continues even when serum osmolality is decreased, causing marked water retention and dilutional hyponatremia. SIADH may occur as a transient condition, as in a stress situation, or, more commonly, as a chronic condition, resulting from disorders such as lung or brain tumors. Tumors, particularly bronchogenic carcinomas and cancers of the lymphoid tissue, prostate, and pancreas, are known to produce and release ADH independent of normal hypothalamic control mechanisms. The manifestations of SIADH are those of dilutional hyponatremia. Urine osmolality is high and serum osmolality is low. Urine output decreases despite adequate or increased fluid intake. Hematocrit and the plasma sodium and blood urea nitrogen levels are all decreased because of the expansion of the extracellular fluid volume.
What is the nurse's expectation about a client's ability to compensate for a metabolic blood gas disorder? The client will compensate with the respiratory system. The client will not be able to compensate. The client will compensate with the same system. The client's breathing will slow down.
The client will compensate with the respiratory system. Explanation: The one thing that a nurse can expect is that a client with a metabolic disorder will compensate with the respiratory system. The client cannot compensate with the same system. The nurse cannot expect the client's breathing to slow down as in some cases it will increase, depending on the primary disorder.
Potassium is the major cation in the body. It plays many important roles, including the excitability of nerves and muscles. Where is this action particularly important? The heart The brain The lungs The liver
The heart Explanation: Changes in nerve and muscle excitability are particularly important in the heart, where alterations in plasma potassium can produce serious cardiac dysrhythmias and conduction defects. Reference:
A client with a long history of alcohol abuse has been admitted to the emergency department after several of days of heavy drinking. The nurse can best promote the restoration of the client's acid-base balance by: encouraging pursed-lip breathing and deep breathing and coughing exercises. administering intravenous sodium bicarbonate as prescribed. administering intravenous magnesium sulfate as prescribed. positioning the client in an upright position when in bed and mobilizing the client frequently.
administering intravenous sodium bicarbonate as prescribed. Explanation: Sodium bicarbonate is among the more common treatments for the metabolic acidosis that results from high alcohol intake. Breathing exercises do not have appreciable effect, though respiratory compensation will likely be taking place. Magnesium sulfate addresses a likely electrolyte imbalance, not an acid-base imbalance. The client's position will have a negligible effect on acid-base balance.
As other mechanisms prepare to respond to a pH imbalance, immediate buffering is a result of increased: intracellular albumin. hydrogen/potassium binding. sodium/phosphate anion absorption. bicarbonate/carbonic acid regulation.
bicarbonate/carbonic acid regulation. Explanation: The bicarbonate buffering system, which is the principal ECF buffer, uses H2CO3 as its weak acid and bicarbonate salt such as sodium bicarbonate (NaHCO3) as its weak base. It substitutes the weak H2CO3 for a strong acid such as hydrochloric acid or the weak bicarbonate base for a strong base such as sodium hydroxide. The bicarbonate buffering system is a particularly efficient system because its components can be readily added or removed from the body. Hydrogen and potassium exchange freely across the cell membrane to regulate acid-base balance. Sodium is not part of the buffering system. Intracellular protein is part of the body protein buffer system; albumin is extracellular.